So as not to ignore the OP (sorry, we tend to get off topic here at times!), I would generally say that learning to read would not improve IQ scores. Improved motor efficiency, especially in the area of small motor skills, might improve processing speed scores, though.

Back to the OT discussion...

This article is one that argues against profile analysis: http://www.gifted.uconn.edu/siegle/Publications/PsychInSchoolBestPractices.pdf
Around the bottom of the fourth page, they begin that discussion.

The WISC technical report #3, on the other hand (
) essentially seems to support profile analysis by giving the typical scoring patterns for children with various disabilities. I do wish that they had included 2e kids in this chart, too, though and the typical gifted scores they showed seemed awfully low to me in areas like VCI and PRI.

A couple articles discussing slower processing in gifted children (and, again, I really don't think that the OP's child qualifies as having slower processing here):

http://www.davidsongifted.org/db/Articles_id_10447.aspx
http://www.gifteddevelopment.com/About_GDC/whoaregiftd.htm